Cancer is the chaotic search for adaptation to previously unknown environments.

DESCRIPTION: Cancer may be the most important global public health problem. The effort of understanding carcinogenesis has been accelerating over the last years on account of its high incidence and impact on the lives of individuals' affected. There are a number of theories of carcinogenesis and these theories may be used to justify various alternative cancer treatments. The small variations in cancer mortality observed during the previous years indicate that the clinical applications of these theories have been very limited. In this article, we tried to explain carcinogenesis based on complex adaptive system (CAS) theory.